Lubricating device



Oct. 13, 1953 R. ANNEN LUBRICATING DEVICE Filed April 10, 1950 MM. 414M iatenteri Oct. 13, 1953 LUBRICATING DEVICE Robert Annen, Bienne, Switzerland, assignor to Roulements a Billes Miniatures S. A., Bienne,

Switzerland Application April 10, 1950, Serial No. 154,970 In Switzerland May 5, 1949 The present invention relates to lubricating devices, and more especially to devices for automatically lubricating bearings of vertical shafts. The invention relates particularly, though by no means exclusively, to the bearings of shafts in gyroscopes.

The lubrication of bearings of vertical shafts rotating at high speed, where friction is to be reduced to a minimum, poses serious problems. The prior art has attempted to cope with these problems by the introduction, into the bearings, of a very small quantity of oil which had to be renewed frequently. This procedure has been followed, for example, in lubricating the ball bearings of gyroscopes. Frequent renewal of the lubricant, however, has the serious disadvantage of requiring cleaning and, consequently, taking the device apart every time the lubricant had to be exchanged, thus involving, manifestly, an excessively costly procedure.

The primary object of this invention is to eliminate the frequent renewals of the lubricant, and the disadvantages resulting therefrom.

Other objects, and the manner in which the same are attained, will become apparent as this specification proceeds.

The invention contemplates the enclosure of each of the bearings in an envelope comprising a trough-shaped portion located below the bearing and constituting an oil reservoir from which the oil is elevated to the bearing during rotation of the shaft, by means of a shaft portion having an upwardly increasing diameter, the envelope portion penetrated by the shaft being spaced from the latter by a capillary gap whereby to prevent the oil from escaping from the space in which the bearing is enclosed.

The annexed drawings illustrate, diagrammatically and by way of example, several embodiments of the lubricating device according to the invention.

Figs. 1,2 and 3 are longitudinal sectional views of a first, second and third embodiment, respectively, adapted to ball bearings, roller bearings and sliding bearings, respectively.

Fig. 4 is a partly sectional view of a detail of any one of the three embodiments on an enlarged scale, and

Fig. 5 is an elevational, partly sectional view of an embodiment intended for larger size bearings.

Referring now to the drawings wherein like elements are indicated by identical reference numerals, and first to Fig. 1, a housing I is shown to enclose an apparatus comprising a vertical 5 Claims. (Cl. 308-134.1)

shaft 2. The upper and lower ends of this shaft rotate in bearings comprising outer race-rings 3 and 4, respectively, and rows of balls 5 and 5', respectively, mounted in cages 6 and 6', respectively.

The ring 3 forming part of the upper bearing is pressed into a bore of the housing I and constitutes the cylindrical portion of an envelope enclosing the bearing. This envelope is closed at its lower end by a trough 1 made of hardened steel, for example, and at its upper end by a membrane 8 made of synthetic material such as synthetic rubber, for example; the peripheral portion of this membrane is pressed down onto the:

upper end face of the ring 3 by means of a screw 9 having a central recess It].

The trough i has a central aperture bordered.

by a conical tubular portion II. This portion H surrounds a conical collar I2 provided on shaft: 2, with a clearance not exceeding in width some: As shown in Fig.

hundredths of millimeter. the upper edge of the tubular portion H approaches the plane of the base [3 of collar I2: without reaching it entirely. The clearance between the portion 1 l of the trough I and the edge of the collar [2 of shaft 2, creates a capillary gap l4, permitting the trough 1 to act as an oil reservoir preventing escape of the oil Whether the shaft rotates or not. During rotation of the shaft the oil adhering to the collar l2 and to the bottom portion II along the capillary ga is thrown into the reservoir along the edge It which, as has been described above, is located in a plane above that of the upper edge of the tubular portion ll of the trough I. The trough i also has a peripheral or flange portion l6 pressed into the ring 3, and which extends to a certain plane; a shaft portion ll' now to be described, extends to substantially the same plane.

The shaft portion I! has an inverted frustoconical section, its diameter increasing upwardly from the base 13 of the collar l2 to the inner raceway of the bearing, which raceway has been worked into the material of shaft 2. During rotation of the shaft, the body of oil contained in the reservoir I8 climbs along the shaft portion i! owing to the combined action of the centrifugal force and the surface tension. After having lubricated the inner and outer raceways, the oil returns to the reservoir [8 along the inner peripheries of ring 3 and the flange It.

The central recess H) in the screw 9 is connected with the space below the trough l, by a notch [9, provided in the screw 9, and by an annular groove 20 and a lon itudinal channel 2| closed in an envelope whose cylindrical portion is constituted by the outer race-ring 4 and clo s ed i at its bottom end by a disc 22, made of a slightly compressible material, and' 'having-it s peripheralportion clamped between a shoulder -2-3- of' the housing I and the lower end face of the racering 4. At its upper end, theengelppc isfilqfififl by a cover 24 whose peripheral flange 25 1s; pressed into the race-ring an internal flange 26 bordering an aperture in this cover, surrounding a collar 21 provided on shaft 2, with aclearance of a width 5 not exceeding some :.hundredths of a=millimeter, thus creating acapillaryga p28.

The lower .portionof the envelope constitutes an oil reservoir 29:: This.-reservoir is coveredby a disc 39 fixed in the race-ring 4 and surround ing the conicalendsection.3lof shaft =2 with a radial clearance of a -.width ofsome hundredths of .-a.. millimeter. V Theoil travels from thereservoir-29 along the conical portion 3! 'of the shaft 2 Ito the row of I balls :5 owing to the surface tension. andrthe centrifugal force acting-on the 'oilduringrotation of shaft-2. Removal of oil-from the reservoir :results in-a reduction ofthe pres sure therein so that -air is sucked in through a very narrow bore 32- providedin-the disc'3i,- near its periphery. The oil' fiowingalong the'inner wall of the race-ring-A afterhavinglubricated the raceways, clogs thebore 32-and flows on-the slightlyconcave surface ofthe disc towards the conical end-portiontl ofshaft-Z. The air pressure in the oil reservoir 29 is slightly reduced as long as the shaft rotates.

In the assembly of -the apparatus; preferably the reservoirs 8 and ZS-are filled wit-h oil before theshaft Z is mounted in-place the upper bearing being inverted,and the shaft then placed into the :still invertedbearing. Thereafterthe lowerbearing is placed on the -s haft,-likewise in its inverted position whereby the oil is'cau sed to slowly expand over the surface of; the disc 30, while. the air pressure in the reservoir "29 is;;reduced. As soon as'the shaft portion 3| fills the central hole of disc ;3 .,:the oilceases flowing. Nowhonly the final adjustment of the play betweenthe two bearings remains-to be made. The assembly-of the apparatus, however may also proceed with the two bearingsoccupyingthe positions; shown in Fig. by filling heres rr n flilmountin shaft 2 and the upper bearinginposition, filling the reservoir l 8,; and; then mounting.; the membranceB and sc iewd:

The quantity; of oil drawn ;towards--the racee ysof t u per and lower, bearings; may-easily be controlled by-a;suitable, adaptation of the shape of the ;shaft portions l1 ands3l having upwardly; ingreasing diarneters. v If ;the se shaft portions areconical, this; control may involve adaptingv e one-nah: t e co e-to. the spee of-rotation ofthe shafts The embodiments pf figs. 2 and-3 differ from he first embodimentgonly bydifferences in. the types of, bearings ;ernploye d theeznbodiment of Fi ,.2, u ing; o lericbearings including rollers '4 33 and the embodiment of Fig. 3 sliding bearings including sliding surfaces 34 and bushings 35 made of an appropriate material. As shown by Fig. 3, the bushings 35 are provided with longitudinal recesses 35 permitting the oil flowing from the sliding surfaces 34 to return to the oil reservoirs l8 and 29, respectively. All other arrangements remain thelsame as in the first embodiment.

Fig. 5 illustrates another embodiment of the invention, 1. e. a device for lubricating the lower sliding bearing of a vertical shaft 31 having a relatively large diameter. The shaft journal has at its-lower end-a central bore in which is inserted agsleeve 3$;dipping into the oil in reservoir 29": The bottom disc 22' of reservoir 29 is. n ade of slightly compressible material, the

Same-a5. the bottom disc 22 in the embodiment of Fig. 1. During rotation of the shaft 31, cen- -trifugalaction causes the oil to creep along the wall of the conical bored!) and to escape through the radial channels 4|, so as to reach the bushing surface 12 in whichturns the journalof the shaft 31; This modification may be .readily adapted to apparatus involving ball orroller bearings in place. of the. sliding bearings shown in.

Fig. 5.

The invention may-be employed inthe lubrication of intermediate shaft bearings. In that case the intermediate bearing (ofrollen'ballor sliding bearing type) :is enclosed in an envelope the lower portion of which corresponds to the lower end portions l2, 13, I4; I5,v 16.:and ll of one of the upper bearings illustrated -in--Fig.- 1 to l, whereas, the upper portion of the envelope corresponds to the-upper portions, 24, 25, 26, 2'1 and-12.8 .of the lower bearings'shownin- Figssl to4..

t is tobeunderstood-that it is not intended'to limitethescope of the patent to the exact-details of construction, designand operation shown and described as various modifications falling withinthe scope-0f the appended claims and involving no departure from the spiritpfthe invention nor any sacrifice of the advantages thereof, wilt-readily Y suggest themselves to ;a person skilled in the art.

I claim:

Livertical shaft support comprising incombination, a 1 bearing bushing, a shaft 1 journal formed with an inverted frus'toconical axietlsecition -.vertically extending into said bushing and capable of acting as aliquid elevator, an oilres crvo'i-r concentrically arranged-in said bushing and surrounding the narrower part of sa i d J ur-, nal with a' clearance of small capillar yrwidth means for otherwise hermetically sealing or the interior of said bearing, and-elastic means adapt edto; take up ;any--rise of pressure withinlsaid seaiedspace.

ZU The-Shaft-support of claim-l; inwhieh'the elastic sealing means is an elastically expandin membrane held down on the topof the bearing bushing; I I I 3."The shaft support of claiml inwhich the means for sealing off theinterior of said bearing is an inwardlyraised edge surrounding an aper; ture in the bottom portion of the oii reservoir and a journal section of upwardly increasing diameterbelow the frustoconical section; said journal section forming with said raised edgea narrow circular capillary gap.

'4. Theshaft support of claim 1,-in combinationwith a bearing housing; a screw above the bearing'bushing accommodated -in said "housing,

an elastic membrane, which forms the elastic sealing means, held applied onto said bearing bushing by said screw and a cavity in the screw bottom face communicating through a radial notch with the outer air.

5. The shaft support of claim 1 as applied to the bottom end of the shaft in combination with a disc of compressible material sealing a bottom cavity of said bushing, said disc being formed with a narrow vent.

ROBERT ANNEN.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date Waring Oct. 13, 1931 Schuck Aug. 1, 1933 Delaval-Crow May 7, 1935 Colvin Nov. 17, 1936 

